Saliva test to identify depression in boys
Researchers measured the stress hormone cortisol in teenage boys and found that ones with high levels coupled with mild depression symptoms were up to 14 times more likely to suffer clinical depression later in life than those with low or normal cortisol levels.
The test was tried on teenage boys and girls, but found to be most effective with boys.
About one in six people suffer from clinical depression at some point in their lives, and most mental health disorders start before age 24. There is currently no biological test to spot depression.
"This is the emergence of a new way of looking at mental illness," said Professor Joe Herbert of the University of Cambridge, one of the study authors.
"You don't have to rely simply on what the patient tells you, but what you can measure inside the patient," he said.
Professor Herbert compared the new test to ones done for other health problems, such as heart disease, which evaluate